High-performance metal-oxide-semiconductor field effect transistors (MOSFETs) on III–V semiconductors have long proven elusive. High-permittivity (high-$\kappa$ ) gate dielectrics may enable their fabrication. We have studied hafnium oxide and aluminum oxide grown on gallium arsenide by atomic layer deposition. As-deposited films are continuous and predominantly amorphous. A native oxide remains intact underneath $\mathrm{Hf}{\mathrm{O}}_2$ during growth, while thinning occurs during ${\mathrm{Al}}_2{\mathrm{O}}_3$ deposition. Hydrofluoric acid etching prior to growth minimizes the final interlayer thickness. Thermal treatments at $\sim 600°\mathrm{C}$ decompose arsenic oxides and remove interfacial oxygen. These observations explain the improved electrical quality and increased gate stack capacitance after thermal treatments.

We demonstrate undoped-body, gate-all-around (GAA) Si nanowire (NW) MOSFETs with excellent electrostatic scaling. These NW devices, with a TaN/Hf-based gate stack, have high drive-current performance with NFET/PFET I_DSAT = 825/950 ¿A/¿m (circumference-normalized) or 2592/2985 ¿A/¿m (diameter-normalized) at supply voltage V_DD = 1 V and off-current I_OFF = 15 nA/¿m. Superior NW uniformity is obtained through the use of a combined hydrogen annealing and oxidation process. Clear scaling of short-channel effects versus NW size is observed.

We establish the limits of magnetism in thin, electronic grade, hafnium oxide, and hafnium silicate films deposited onto silicon wafers by chemical vapor deposition and atomic layer deposition. To the limits of sensitivity of our measurement techniques, no ferromagnetism occurs in these samples. Contamination by handling with stainless-steel tweezers leads to a measurable magnetic signal. The magnetic properties of this contamination are similar to those attributed to ferromagnetic ${\mathrm{HfO}}_2$ in a recent report, including the magnitude of moment, magnetization field dependence, and spatial asymmetry.